The present invention relates to imaging technology. In particular, it relates to systems and methods that facilitate the measuring and/or imaging of a fluorescent or bioluminescent light source or light source distribution inside a scattering medium, which is particularly useful in biomedical imaging and research applications.
Imaging with light is steadily gaining popularity in biomedical applications. One currently popular light imaging application involves the capture of low intensity light emitted from a biological sample such as a mouse or other small animal. This technology is known as in vivo optical imaging. Light emitting probes that are placed inside the sample typically indicate where an activity of interest might be taking place. In one application, cancerous tumor cells are labeled with light emitting reporters or probes, such as bioluminescent proteins, or fluorescent proteins or dyes.
Photons emitted by labeled cells scatter in the tissue of the mammal, resulting in diffusive photon propagation through the tissue. As the photons diffuse, many are absorbed, but a fraction reaches the surface of the mammal. The photons emitted from surface of the mammal can then be detected by a camera. Light imaging systems capture images that record the two-dimensional (2D) spatial distribution of the photons emitted from the surface.
Using this 2D imaging data and computer-implemented photon diffusion models, a 3D representation of the fluorescent light sources inside a sample can be produced. For instance, a fluorescent probe's 3D location, size, and brightness can be determined using diffusion models. However, since these models are a function of the optical property values for the sample, the accuracy of the 3D light source representation produced by a given model depends on the accuracy of the optical properties that are input into such model.
Improved techniques and apparatus for providing accurate optical properties of a sample or a set of samples are needed.